What does it mean to have a personality disorder?

Personality consists of the well-established patterns of thinking, feeling and behaving that make up individual character. PD (Personality Disorder) is diagnosed when these patterns deviate markedly from the expectations of a particular culture in at least two of the following areas: our thoughts – that is, how we make sense of other people, ourselves, and everyday events – our emotions – how intense, changeable and appropriate they appear to be – the way we relate to other people, and how able we are to control our impulses. PD sufferers complain of feeling alone and isolated, of having difficulty making and maintaining relationships, and of trusting other people. They have relatively high rates of self-harming and suicide attempts. To establish a firm diagnosis, however, their personality pattern must range across a number of situations, be resistant to change, and have been evident since at least late adolescence.

PD is not unusual. In 2006, Jeremy Coid and his colleagues at Queen Mary University in London looked at the prevalence of Personality Disorders in over 600 individuals across the UK. They found a prevalence rate of 4.4%, which makes PD even more common than schizophrenia, bipolar disorder or autistic spectrum disorder. PD sufferers are most often male, and many have had problems with substance misuse. The Diagnostic and Statistical Manual of Mental Disorders lists ten types of PD including Borderline, Paranoid and Antisocial types. However, this complicated classification has been criticised – rightly, I believe – by a number of professionals including those in the British Psychological Society for two reasons. First, most sufferers don’t fit easily into just one category, and second, the categories aren’t helpful when it comes to choosing the best method of treatment.

PD is difficult to treat, mostly because sufferers find it difficult to remain engaged in treatment. Professionals have tried using a number of different approaches, including talking therapies, group work and medication. The most well-researched and widely publicised treatment is Dialectical Behaviour Therapy (DBT), a talking therapy derived from Cognitive Behaviour Therapy. DBT was developed by Professor Marsha Linehan who was herself a PD sufferer. DBT can help anyone with a Personality Disorder, but it’s aimed particularly at those suffering from Borderline PD. DBT offers positive support to build self-esteem and group work to build relationship skills. It also teaches problem solving skills particularly in the context of establishing and maintaining relationships.

It is not yet known what causes PD. While it has been associated with severe neglect and highly insecure and inconsistent parenting, as yet no causal relationship has been established. As with so many psychological disorders, we’ll probably find that there are a number of factors working together including genetic and neurological makeup, as well as particular childhood experiences.

Despite the complexity of this disorder, it can be well managed given the necessary resources and as long as the sufferer is willing to engage in appropriate treatment.

Linda Blair is a clinical psychologist. Her book, The Key to Calm (Hodder & Stoughton, £14.99), is available from Telegraph Books for £12.99. Call 0844 871 1514 or visit books.telegraph.co.uk